Avalanche Forecast

Issued: Dec 6th, 2014 4:00PM

The alpine rating is moderate, the treeline rating is considerable, and the below treeline rating is low. Known problems include Persistent Slabs and Wind Slabs.

max darrah, Parks Canada

Jasper.

Travel conditions are improving as last week's storm snow settles into a supportive midpack. The main concern is the interface between this settled snow and crusts near the bottom of the snowpack, particularly at treeline.

Summary

Weather Forecast

Temperatures to remain mild throughout the week, dropping next Sunday. We expect 5cm in the Icefields area in the next 24 hours and then another 15cm over the course of the week. A steady drop in pressure and cloudy skies throughout the week will accompany the snowfall. Winds will be variable; most intense mid-week from the South.

Snowpack Summary

Settled storm snow at lower elevations and windslab in the alpine. The main concern is the interface between the settled storm snow and several crusts near the bottom of the snowpack. This interface is producing sudden collapse results in test profiles and widespread whumphing at treeline and has been associated with recent natural avalanches.

Avalanche Summary

Field teams reported several full depth avalanches to size 2 on South East aspects at approximately 2400m. These occurred in the last 24 hours.

Confidence

Problems

Persistent Slabs

Storm snow has evolved into a persistent slab mainly around treeline and sheltered alpine slopes. Widespread whumphing in open treeline areas.

Carefully evaluate and use caution around thin snowpack areas.Assess start zones carefully and use safe travel techniques.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Wind Slabs

These slabs are found on exposed slopes and produced moderate to hard test results with failures in the facet layer near the bottom of the snowpack.

Use caution in lee areas. Recent wind loading have created wind slabs.

Aspects: North, North East, East, South East, South.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Dec 7th, 2014 4:00PM